Recently purchased a Bushie M-forgery. I'm completely satsified with the quality, fit and finish.
It took only 10 rounds to get an IBZ. First 250 rounds (some UMC, some Q3131A) have all run without a hitch. Very accurate weapon if I do my part.
I ordered some spare parts and tools (mounted a single point sling) and everything arrived in good order. Got good help over the phone with a question about installing a third party vendor's (GG&G) receiver end plate.
So. . . two months into my relationship with Bushmaster, I've got only good things to say.